package com.jiepos.mpos.core.util;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * @ClassName: RandomValidateCode
 * @Description: 验证码工具类
 * @author 孙永
 * @date 2017年9月26日 下午4:12:49
 */
public class RandomValidateCode {
	
	private static Random random = new Random();
	private static final String randString = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";// 随机产生的字符串
	private static final int width = 87;// 图片宽
	private static final int height = 32;// 图片高
	private static final int lineSize = 40;// 干扰线数量
	private static final int stringNum = 4;// 随机产生字符数量
	private static final String IMAGE_CODE = "imagecode";
	private static final String VALIDATE_CODE = "validateCode";
	
	/**
	 * 获得字体
	 * @return
	 */
	private static Font getFont() {
		return new Font("Fixedsys", Font.CENTER_BASELINE, 25);
	}

	/**
	 * 获得颜色
	 * @param fc
	 * @param bc
	 * @return
	 */
	private static Color getRandColor(int fc, int bc) {
		if (fc > 255){
			fc = 255;
		}
		if (bc > 255){
			bc = 255;
		}
		int r = fc + random.nextInt(bc - fc - 16);
		int g = fc + random.nextInt(bc - fc - 14);
		int b = fc + random.nextInt(bc - fc - 18);
		return new Color(r, g, b);
	}
	
	/**
	 * 绘制字符串
	 * @param g
	 * @param randomString
	 * @param i
	 * @return
	 */
	private static String drowString(Graphics g, String randomString, int i) {
		g.setFont(getFont());
		g.setColor(new Color(random.nextInt(101), random.nextInt(111), random.nextInt(121)));
		String rand = String.valueOf(getRandomString(random.nextInt(randString.length())));
		randomString += rand;
		g.translate(random.nextInt(3), random.nextInt(3));
		g.drawString(rand, 13 * i, 22); // 设置字符串的位置
		return randomString;
	}
	
	/**
	 * 绘制干扰线
	 * @param g
	 */
	private static void drowLine(Graphics g) {
		int x = random.nextInt(width);
		int y = random.nextInt(height);
		int xl = random.nextInt(13);
		int yl = random.nextInt(15);
		g.drawLine(x, y, x + xl, y + yl);
	}
	
	/**
	 * 获取随机的字符
	 * @param num
	 * @return
	 */
	public static String getRandomString(int num) {
		return String.valueOf(randString.charAt(num));
	}
	
	/**
	 * 生成随机图片
	 * @param request
	 * @param response
	 * @param key
	 */
	public static void getRandcode(HttpServletRequest request, HttpServletResponse response) {
		BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR);
		Graphics g = image.getGraphics();// 产生Image对象的Graphics对象,改对象可以在图像上进行各种绘制操作
		g.fillRect(0, 0, width, height);
		g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 25));
		g.setColor(getRandColor(110, 133));
		// 绘制干扰线
		for (int i = 0; i <= lineSize; i++) {
			drowLine(g);
		}
		// 绘制随机字符
		String randomString = "";
		for (int i = 1; i <= stringNum; i++) {
			randomString = drowString(g, randomString, i);
		}
		//1：将随机生成的验证码放入Cookie中
		Cookie cookie = new Cookie(IMAGE_CODE, randomString);
		response.addCookie(cookie);
		
		//2：将随机生成的验证码放入session中
		String sessionid = request.getSession().getId();
		request.getSession().setAttribute(sessionid + IMAGE_CODE, randomString);
		g.dispose();
		try{
			ByteArrayOutputStream tmp = new ByteArrayOutputStream();
			ImageIO.write(image, "png", tmp);
			tmp.close();
			Integer contentLength = tmp.size();
			response.setHeader("content-length", contentLength + "");
			response.getOutputStream().write(tmp.toByteArray());// 将内存中的图片通过流动形式输出到客户端
		}catch(Exception e){
			e.printStackTrace();
		}finally{
			try {
				response.getOutputStream().flush();
				response.getOutputStream().close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
	
	/**
	 * 校验验证码
	 * @param request
	 * @return
	 */
	public static boolean checkCode(HttpServletRequest request){
		try{
			String code = null;
			Cookie[] cookies = request.getCookies();
			for (Cookie cookie : cookies) {
				if (IMAGE_CODE.equals(cookie.getName())) {
					code = cookie.getValue();
					break;
				}
			}
			String validateCode = request.getParameter(VALIDATE_CODE);
			if(!StringUtils.isEmpty(validateCode) && validateCode.equalsIgnoreCase(code)){
				return true;
			}
		}catch(Exception e){
			e.printStackTrace();
		}
		return false;
	}
}
